Method and device for communicating messages within a 5G network

ABSTRACT

A device may receive, from an application function device (AF), a message intended for a destination user device, wherein the message conforms to a first format. The device may obtain, from a unified data management device (UDM), information indicating that the destination user device is capable of receiving messages that conform to a second format. The device may convert, based on the information indicating that the destination user device is capable of receiving messages that conform to the second format, the message from the first format to the second format. The device may send, after converting the message from the first format to the second format, the message to a short message service function device (SMSF) via a direct connection between the device and the SMSF, wherein the SMSF sends the message to the destination user device.

RELATED APPLICATIONS

This application is a Continuation-In-Part (CIP) of U.S. patentapplication Ser. No. 16/777,041, filed on Jan. 30, 2020, which is aContinuation of U.S. patent application Ser. No. 16/228,180, filed Dec.21, 2018, the contents of which are incorporated by reference herein intheir entirety.

BACKGROUND

Short message service (SMS) is commonly known as text messaging. An SMSmessage may be sent from one user device to another user device via oneor more wireless telecommunications systems, such as a long termevolution (LTE) wireless telecommunications system, a 3G wirelesstelecommunications system, a 4G wireless telecommunications system, anLTE-Advanced (LTE-A) wireless telecommunications system, a 5G wirelesstelecommunications system, and/or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1F are diagrams of one or more example implementationsdescribed herein.

FIG. 2 is a diagram of an example environment in which systems and/ormethods described herein may be implemented.

FIG. 3 is a diagram of an example environment illustrating at least onebenefit of some implementations described herein.

FIG. 4 is a diagram of example components of one or more devices of FIG.2.

FIGS. 5A-5B are diagrams of call flows of example operations capable ofbeing performed by one or more devices of FIG. 2 and/or one or morecomponents of one or more devices of FIG. 2.

FIG. 6 is a flow chart of an example process for a method and device forcommunicating messages within a 5G network.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The following detailed description of example implementations refers tothe accompanying drawings. The same reference numbers in differentdrawings may identify the same or similar elements.

To support text messaging, a 5G telecommunications system includes ashort message service (SMS) function device (SMSF) to enable SMSmessages to be transmitted through the 5G telecommunications system. Inmany cases, however, to transmit an SMS message to a destination userdevice, the SMSF sends an SMS message to a short message service centerdevice (SMSC) of another telecommunications system, such as a long termevolution (LTE) telecommunications system, which sends the SMS toanother device, such as a network exposure function device (NEF), of the5G telecommunications system. Consequently, currently sending an SMSmessage using the SMSF is convoluted and causes excessive statusmessages (at least about nine additional status messages) to betransmitted between different network devices of the 5Gtelecommunications system. In many cases, this increases the complexityof identifying network device issues because it is hard to determine anorigination point of an SMS messaging error. Moreover, transmitting SMSmessages across telecommunications systems can affect latency and/orother quality of service characteristics associated with transmittingthe SMS messages.

Some implementations described herein provide a network exposure device(e.g., a network exposure function (NEF)) that communicates messages,including SMS messages, with a message transmission device (e.g., anSMSF) via a direct connection between the network exposure device andthe message transmission device (e.g., without communicating with a SMSCof another telecommunications system). In some implementations, thenetwork exposure device may receive a message intended for a destinationuser device and/or an application function (AF). In someimplementations, when the message is intended for the destination userdevice, the network exposure device may process the message based on atleast one communication capability of the destination user device (e.g.,by converting the message into a format that the destination user deviceis capable of receiving). In some implementations, the network exposuredevice may send the message to the message transmission device via thedirect connection and the message transmission device may send themessage to the destination user device. In some implementations, whenthe message is intended for the AF, the network exposure device mayprocess the message (e.g., by converting the message into a format thatcomplies with an interface format used by an interface between thenetwork exposure device and the AF) and may send the message to the AF.

In this way, some implementations provide a network exposure device thatallows standard network devices to communicate messages within a 5Gtelecommunication system (e.g., without the messages being communicatedto or from another telecommunications system). Accordingly, messages maybe more directly routed via the network devices, which may reduce theamount of status messages that need to be communicated between thenetwork devices to send and/or receive a message. This may reduce usageof network device resources (e.g., processor resources, memoryresources, communication resources, power resources, and/or the like) tocommunicate the messages. Furthermore, this allows numerous types ofmessages, not just SMS messages, to be communicated via the 5Gtelecommunications system in a uniform, predictable way. This may alsoallow user devices and/or AFs to communicate messages that are optimizedfor 5G telecommunications, which may further reduce usage of networkdevices resources.

FIGS. 1A-1F are diagrams of one or more example implementations 100described herein. Example implementation(s) 100 illustrate variousportions of a wireless telecommunications systems, such as a 5G wirelesstelecommunications system. As shown in FIG. 1A, exampleimplementation(s) 100 may include one or more user devices (shown asuser devices 102-1 through 102-L) connected to one or more radio accessnetworks (RANs) at one or more base stations (shown as gNB 104-1 through104-M), such as one or more gNBs associated with a 5G telecommunicationssystem. For example, a first set of user devices (e.g., one or more userdevices 102-1) may be wirelessly connected with gNB 104-1 and a secondset of user devices (e.g., one or more user devices 102-L) may bewirelessly connected with gNB 104-M. In some implementations, a userdevice of the one or more user devices may have at least onecommunication capability. For example, a communication capability mayhave a capability to send and receive messages that conform to one ormore formats, such as a non-access stratum (NAS) format, a short messageservice (SMS) format, a service based interface (SBI) format (e.g., aformat suitable for being transmitted via an SBI), a representationalstate transfer (REST) application programming interface (API) format,and/or the like.

As further shown in FIG. 1A, a base station of the one or more basestations may be connected to an access management network device (shownas AMF 106-1 through 106-N), such as an access and mobility managementfunction (AMF) associated with the 5G telecommunications system. Forexample, gNB 104-1 may be connected to AMF 106-1 and gNB 104-M may beconnected to AMF 106-N. In some implementations, an access managementnetwork device may communicate with a set of user devices, of the one ormore user devices, via a base station of the one or more base stations.In some implementations, the access management network device maycommunicate with the set of user devices to determine, for each userdevice of the set of user devices, information concerning a reachabilityof the user device. In some implementations, the information concerningthe reachability of the user device may include a reachability status ofthe user device (e.g., whether the user device is active, awake, asleep,idle, connected, and/or the like); a reachability time of the userdevice (e.g., a time when the user device is reachable, a duration oftime the user device is reachable, a reachability start time of the userdevice, a reachability end time of the user device, a schedule of whenthe user device is reachable and/or for how long, and/or the like);and/or the like. In some implementations, the access management networkdevice may store the information concerning the reachability of the userdevice.

As further shown in FIG. 1A, the access management network device may beconnected to a message transmission device (shown as SMSF 108), such asan SMS function (SMSF) associated with the 5G telecommunications system.In some implementations, the message transmission device may facilitatetransmission of messages to and from the one or more user devices, asdescribed herein. In some implementations, the message transmissiondevice may be connected to a data management network device (shown asUDM 110), such as a unified data management (UDM) associated with the 5Gtelecommunications system. In some implementations, the data managementnetwork device may store information concerning the communicationcapabilities of the one or more user devices. For example, theinformation may include, for at least one user device of the one or moreuser devices, at least one communication capability of the user device.

In some implementations, the message transmission device may beconnected to a network exposure device (shown as NEF 112), such as anetwork exposure function (NEF) associated with the 5Gtelecommunications system. In some implementations, the network exposuredevice may include one or more components (shown as SBI adaptor 114, SMSadaptor 116, AF message handler 118, and routing data structure 120) forfacilitating transmission of messages from and to the network exposuredevice, such as an SBI adaptor for facilitating transmission of SBImessages, such as REST API messages, an SMS adaptor for facilitatingtransmission of SMS messages, an AF message handler for facilitatingtransmission of messages to an application network device, a routingdata structure for storing messages, and/or the like. In someimplementations, the one or more components may be separate from eachother and/or separate from the network exposure device (e.g., eachcomponent of the one or more components may be a separate device thatmay or may not be connected to the network exposure device).

In some implementations, the network exposure device may be directlyconnected to the message transmission device and/or the data managementnetwork device. For example, NEF 112 may be directly connected to SMSF108 and/or UDM 110. In some implementations, the network exposure devicemay be connected to the message transmission device and/or the datamanagement network device via respective SBIs, REST APIs, and/or thelike. In some implementations, the network exposure device may bedirectly connected to the application network device (shown as AF 122),such as an application function (AF) associated with the 5Gtelecommunications system. In some implementations, the network exposuredevice may be directly connected to the application network device viaan SBI, a REST API, a T8 interface, and/or the like.

As shown in FIG. 1B and by reference number 124, the application networkdevice (e.g., AF 122) may send a first message to the network exposuredevice (e.g., NEF 112). In some implementations, the first message maybe intended for a destination user device (e.g., user device 102-1). Insome implementations, the first message may conform to a REST APIformat, an SBI format, a T8 format (e.g., a format suitable for beingtransmitted via a T8 interface), and/or the like. For example, the firstmessage may be a REST API message, an SBI message, a T8 message, and/orthe like. In some implementations, the network exposure device mayreceive the first message from the application network device.

As shown by reference number 126, the network exposure device may obtaininformation indicating at least one communication capability of thedestination user device. In some implementations, the information mayindicate that the destination user device is capable of receivingmessages that conform to a particular format, such as an NAS format, anSMS format, an SBI format, a REST API format, and/or the like. In someimplementations, the network exposure device may obtain the informationfrom the data management network device (e.g., UDM 110). For example,the network exposure device may send a query to the data managementnetwork device concerning a messaging capability of the destination userdevice. The data management network device may process the query anddetermine a response that indicates that the destination user device iscapable of sending and/or receiving messages that conform to theparticular format. The data management network device may send theresponse to the network exposure device.

As shown by reference number 128, the network exposure device (e.g., NEF112) may process (e.g., using the AF message handler 118) the firstmessage (e.g., to change, modify, update, and/or the like the firstmessage). In some implementations, the network exposure device mayconvert the first message from a first format to a second format (e.g.,based on the information indicating the at least one communicationcapability of the destination user device). For example, the networkexposure device may convert the first message from an SBI format, a RESTAPI format, and/or the like to a NAS format, an SMS format, and/or thelike based on information indicating that the destination user device iscapable of receiving messages that conform to the NAS format, the SMSformat, and/or the like. In this way, the network exposure device maycause the first message to conform to a particular format that thedestination user device is capable of receiving, decoding, processing,and/or the like.

In some implementations, the network exposure device may determine(e.g., based on the information indicating the at least onecommunication capability of the destination user device or otherinformation associated with the user device) a location associated withthe destination user device (e.g., a physical location of thedestination user device, a location in the 5G telecommunications system,and/or the like). The network exposure device may select, based on thelocation associated with the destination user device, a messagetransmission device (e.g., SMSF 108), of one or more messagetransmission devices, to receive the first message.

As shown by reference number 130, the network exposure device (e.g., NEF112) may send the first message (e.g., after processing the firstmessage) to the message transmission device (e.g., SMSF 108, theselected message transmission device) via the direct connection betweenthe network exposure device and the message transmission device. In someimplementations, the network exposure device may use one or morecomponents, such as the SBI adaptor (e.g., SBI adaptor 114) and/or theSMS adaptor (e.g., SMS adaptor 116), to send the first message. Forexample, when the first message is a REST API message, the networkexposure device may send the first message to the message transmissiondevice using the SBI adaptor. As another example, when the first messageis an SMS message (e.g., an SMS TPDU message), the network exposuredevice may send the first message to the message transmission deviceusing the SMS adaptor. In some implementations, the network exposuredevice may add the first message to a payload of a message that conformsto a particular format (e.g., an SBI format, a REST API format, a NASformat, an SMS format, and/or the like) before sending the first messageto the message transmission device. For example, the messagetransmission device may add the first message to a payload of an SBImessage, a REST API message, a NAS message, an SMS message, and/or thelike.

As shown by reference number 132, the message transmission device maygenerate (e.g., based on receiving the first message) a paging requestand may send the paging request to the destination user device (e.g.,user device 102-1). For example, the message transmission device maysend the paging request to the access management network device (e.g.,AMF 106-1) associated with the destination user device, which may sendthe paging request to the base station associated with the destinationuser device (e.g., gNB 104-1), which may send the paging request to thedestination user device (e.g., user device 102-1). In someimplementations, the paging request may indicate that the messagetransmission device will send the first message to the destination userdevice (e.g., after receiving a paging response from the destinationuser device).

As shown by reference number 134, the destination user device maydetermine (e.g., based on the paging request) a paging response and sendthe paging response to the message transmission device (e.g., SMSF 108).For example, the destination user device may send the paging response tothe base station (e.g., gNB 104-1), which may send the paging responseto the access management network device (e.g., AMF 106-1), which maysend the paging response to the message transmission device (e.g., SMSF108). In some implementations, the paging response indicates that thedestination user device is ready to receive the first message (e.g.,that the destination user device is reachable). For example, the pagingresponse may indicate that the destination user device is notcommunicating with any other network devices (and therefore hasbandwidth to receive the first message).

As shown by reference number 136, the message transmission device mayprocess the paging response. In some implementations, the messagetransmission device may process the paging response to determine thatthe message transmission device is to send the first message to thedestination user device (e.g., user device 102-1). For example, themessage transmission device may determine, based on the paging response,that the destination user device is ready to receive the first messagevia the access management network device (e.g., AMF 106-1) and/or thebase station (e.g., gNB 104-1).

As shown in FIG. 1C and by reference number 138, the messagetransmission device (e.g., SMSF 108) may send the first message to thedestination user device (e.g., user device 102-1). For example, themessage transmission device may send the first message to the accessmanagement network device associated with the destination user device(e.g., AMF 106-1), which may send the first message to the base stationassociated with the destination user device (e.g., gNB 104-1), which maysend the first message to the destination user device (e.g., user device102-1).

As shown by reference number 140, the destination user device maygenerate a response message and may send the response message to themessage transmission device (e.g., SMSF 108). For example, thedestination user device may send the response message to the basestation associated with the destination user device (e.g., gNB 104-1),which may send the response message to the access management networkdevice associated with the destination user device (e.g., AMF 106-1),which may send the response message to the message transmission device(e.g., SMSF 108). In some implementations, the response message mayinclude information indicating receipt of the first message by thedestination user device. For example, the response may indicate that thedestination user device received the first message, decoded the firstmessage, processed the first message, and/or the like.

As shown by reference number 142, the message transmission device maysend the response message to the network exposure device (e.g., NEF 112)via the direct connection between the message transmission device andthe network exposure device. As shown by reference number 144, thenetwork exposure device may process the response message. For example,the network exposure device may determine, based on the responsemessage, that the destination user device received, decoded, processed,and/or the like the first message. As shown by reference number 146, thenetwork exposure device may generate and send, based on the responsemessage, a delivery message to the application network device (e.g., AF122). The delivery message may indicate whether the destination userdevice successfully received, decoded, processed, and/or the like thefirst message.

As shown in FIG. 1D and by reference number 148, the network exposuredevice (e.g., NEF 112) may generate a first acknowledgment (e.g.,indicating that the network exposure device received the responsemessage and/or that the network exposure device processed the responsemessage) and send the first acknowledgment to the message transmissiondevice (e.g., SMSF 108) via the direct connection between the networkexposure device and the message transmission device. As shown byreference number 150, the message transmission device may send the firstacknowledgment to the destination user device. For example, the messagetransmission device may send the first acknowledgment to the accessmanagement network device associated with the destination user device(e.g., AMF 106-1), which may send the first acknowledgment to the basestation associated with the destination user device (e.g., gNB 104-1),which may send the first acknowledgment to the destination user device(e.g., user device 102-1).

As shown in FIG. 1E and by reference number 152, an access managementnetwork device (e.g., AMF 106-1) may send a list of a plurality of userdevices to the message transmission device (e.g., SMSF 108). The list ofthe plurality of user devices may indicate a respective reachability ofat least one user device of the plurality of user devices (e.g., userdevices 102-1 through 102-L). For example, the list of the plurality ofuser devices may include information concerning the reachability of auser device, such as the reachability status of the user device, the atleast one time during which the user device is reachable, and/or thelike. As shown by reference number 154, the message transmission devicemay send the list of the plurality of user devices to the networkexposure device (e.g., NEF 112) via the direct connection between themessage transmission device and the network exposure device. In someimplementations, the network exposure device may store the list of theplurality of user devices in a data structure (e.g., routing datastructure 120).

As shown by reference number 156, an originating user device (e.g., userdevice 102-1) may generate a second message. For example, a user of theoriginating user device may enter information into the originating userdevice, via a user interface of the originating user device, to causethe user device to generate the second message. In some implementations,the second message may conform to a NAS format, an SMS format, an SBIformat, a REST API format, and/or the like. For example, the firstmessage may be an NAS message, an SMS message, an SMS transfer protocoldata unit (TPDU) message, an SBI message, a REST API message, a REST APImessage that includes an SMS TPDU message, and/or the like. In someimplementations, the second message may be intended for a destinationuser device (e.g., another user device other than the originating userdevice, such as user device 102-L). Additionally, or alternatively, thesecond message may be intended for the application network device (e.g.,AF 122). In some implementations, the second message may includeinformation that indicates whether the second message is intended forthe destination user device, the application network device, and/or thelike.

As shown by reference number 158, the originating user device may sendthe second message to the message transmission device (e.g., SMSF 108).For example, the originating user device may send the second message toa base station associated with the originating user device (e.g., gNB104-1), which may send the second message to an access managementnetwork device associated with the originating user device (e.g., AMF106-1), which may send the second message to the message transmissiondevice.

As shown by reference number shown by reference number 160, the messagetransmission device may send the second message to the network exposuredevice (e.g., NEF 112) via the direct connection between the messagetransmission device and the network exposure device. As shown byreference number 162, the network exposure device may process the secondmessage. For example, the network exposure device may determine whetherthe second message is intended for the destination user device (e.g.,user device 102-L) and/or the application network device (e.g., AF 122).

As shown in FIG. 1F and by reference number 164, the network exposuredevice may generate a second acknowledgment (e.g., indicating that thenetwork exposure device received the second message and/or that thenetwork exposure device processed the second message) and may send thesecond acknowledgment to the originating user device (e.g., user device102-1). For example, the network exposure device may send the firstacknowledgment to the message transmission device (e.g., SMSF 108) viathe direct connection between the network exposure device and themessage transmission device, which may send the first acknowledgment tothe access management network device (e.g., AMF 106-1), which may sendthe first acknowledgment to the base station (e.g., gNB 104-1), whichmay send the first acknowledgment to the originating user device (e.g.,user device 102-1).

As shown by reference number 166, when the second message is intendedfor the destination user device (e.g., user device 102-L), the networkexposure device (e.g., NEF 112) may determine a reachability of thedestination user device. For example, the network exposure device maydetermine a reachability status of the destination user device, a timewhen the destination user device is reachable, a duration of time thedestination user device is reachable, a reachability start time of thedestination user device, a reachability end time of the destination userdevice, a schedule of when the destination user device is reachableand/or for how long, and/or the like. In some implementations, thenetwork exposure device may determine the reachability of thedestination user device based on the list of the plurality of userdevices stored in the data structure (e.g., routing data structure 120).For example, the network exposure device may search for an entryconcerning the destination user device in the list of the plurality ofuser devices and obtain the information concerning the reachability ofthe destination user device.

In some implementations, the network exposure device may determine atleast one time during which the destination user device is reachablebased on the reachability of the destination user device. In someimplementations, the network exposure device may determine, based on theat least one time during which the destination user device is reachable,that the destination user device is not reachable and may send the firstmessage to the data structure (e.g., routing data structure 120) forstorage. For example, the network exposure device may determine that thedestination user device is not currently reachable (e.g., user device102-L is asleep, inactive, and/or the like) and cause the first messageto be stored in the data structure until the destination user device isreachable again. In some implementations, the network exposure devicemay determine, based on the at least one time during which thedestination user device is reachable, that the destination user deviceis reachable and obtain the first message from the data structure. Forexample, the network exposure device may determine that the destinationuser device is currently reachable (e.g., user device 102-L is awake,active, and/or the like) after a period of not being reachable, andobtain the first message from the data structure.

In some implementations, the network exposure device may determine(e.g., by searching the list of the plurality of user devices stored inthe data structure) that the destination user device is not reachableand/or that the destination user device is not a valid and/or aregistered user device. In some implementations, the network exposuredevice may send an error message to the originating user device (e.g.,user device 102-1) via the message transmission device (e.g., SMSF 108),the access management network device (e.g., AMF 106-1) and/or the basestation (e.g., gNB 104-1) associated with the originating user device.

As shown by reference number 168, the network exposure device may send(e.g., after determining that the destination user device is reachable)the second message to the message transmission device via the directconnection between the network exposure device and the messagetransmission device. In some implementations, the network exposuredevice may use the one or more components of the network exposuredevice, such as the SBI adaptor (e.g., SBI adaptor 114) and/or the SMSadaptor (e.g., SMS adaptor 116), to send the second message. Forexample, when the second message is a REST API message, the networkexposure device may send the second message to the message transmissiondevice using the SBI adaptor. As another example, when the secondmessage is an SMS TPDU message, the network exposure device may send thesecond message to the message transmission device using the SMS adaptor.In some implementations, the network exposure device may convert thesecond message to a different format (e.g., as described elsewhereherein) before sending the second message to the message transmissiondevice. For example, the network exposure device may convert the secondmessage to a format that can be received, processed, and/or the like bythe destination user device.

As shown by reference number 170, the message transmission device maysend the second message to the destination user device (e.g., userdevice 102-L). For example, the message transmission device may send thesecond message to an access management network device associated withthe destination user device (e.g., AMF 106-N), which may send the secondmessage to a base station associated with the destination user device(e.g., gNB 104-M), which may send the second message to the destinationuser device. In some implementations, the destination user device maygenerate and send a response message to message transmission deviceand/or the network exposure device in a similar manner as describedelsewhere herein (see e.g., FIG. 1C and reference numbers 140 and 142).

Additionally, or alternatively, as shown by reference number 172, thenetwork exposure device (e.g., NEF 112) may determine that the secondmessage is intended for the application network device (e.g., AF 122)(rather than the destination user device). For example, the originatinguser device may send the second message to the application networkdevice to report an event experienced by the originating user device. Insome implementations, the network exposure device may convert the secondmessage to a different format before sending the second message to theapplication network device. In some implementations, the networkexposure device may convert the second message to a format that may besent to the application network device via the interface between thenetwork exposure device and the application network device. For example,when the first message is an SMS TPDU message, a REST API message thatincludes an SMS TPDU message, and/or the like, the SMS adaptor (e.g.,SMS adaptor 116) and/or the AF message handler (e.g., AF message handler118) may process the first message to convert the first message into aT8 message (e.g., a message suitable for being transmitted via a T8interface), a REST API message, an optimized REST API message (e.g., aREST API message where unnecessary information concerning the SMS TPDUmessage included in the REST API message has been removed), and/or thelike.

As indicated above, FIGS. 1A-1F are provided merely as examples. Otherexamples can differ from what was described with regard to FIGS. 1A-1F.Further, the number and arrangement of devices and networks shown inFIGS. 1A-1F are provided as an example. In practice, there may beadditional devices and/or networks, fewer devices and/or networks,different devices and/or networks, or differently arranged devicesand/or networks than those shown in FIGS. 1A-1F. Furthermore, two ormore devices shown in FIGS. 1A-1F may be implemented within a singledevice, or a single device shown in FIGS. 1A-1F may be implemented asmultiple, distributed devices. Additionally, or alternatively, a set ofdevices (e.g., one or more devices) of example implementation 100 mayperform one or more functions described as being performed by anotherset of devices of example implementation 100.

FIG. 2 is a diagram of an example environment 200 in which systemsand/or methods, described herein, may be implemented. As shown in FIG.2, environment 200 may include one or more user devices 205-1 through205-L (L≥1) (hereinafter referred to collectively as “user devices 205,”and individually as “user device 205”), one or more base stations 210-1through 210-M (M≥1) (hereinafter referred to collectively as “basestations 210,” and individually as “base station 210”), one or moreaccess and mobility management functions (AMFs) 215-1 through 215-N(N≥1) (hereinafter referred to collectively as “AMFs 215,” andindividually as “AMF 215”), a short message service (SMS) function(SMSF) 220, a unified data management (UDM) 225, a network exposurefunction (NEF) 230, a service based interface (SBI) adaptor 235, an SMSadaptor 240, an application function (AF) message handler 245, a routingdata structure 250, and an application function (AF) 255. Devices ofenvironment 200 may interconnect via wired connections, wirelessconnections, or a combination of wired and wireless connections.

User device 205 includes one or more devices capable of receiving,generating, storing, processing, and/or providing information, such asinformation described herein. For example, user device 205 may include acommunication device, such as an Internet of Things (IoT) device (e.g.,a category M1 (Cat-M1) device, a narrow band (NB) IoT device, and/or thelike), a mobile phone (e.g., a smart phone, a radiotelephone, etc.), alaptop computer, a tablet computer, a handheld computer, a gamingdevice, a wearable communication device (e.g., a smart wristwatch, apair of smart eyeglasses, etc.), or a similar type of device. In someimplementations, user device 205 may generate information, such as amessage, a paging response message, a response message, a deliverymessage, and/or the like, and send the information to AMF 215, SMSF 220,and/or NEF 230 via base station 210. In some implementations, the userdevice may receive information, such as a message, a paging requestmessage, and/or the like, from AMF 215, SMSF 220, and/or NEF 230 viabase station 210.

Base station 210 includes one or more devices capable of transferringtraffic, such as audio, video, text, one or more messages, and/or othertraffic, to or from user device 205 and/or AMF 215. In someimplementations, base station 210 may include a small cell base station,such as a base station of a microcell, a picocell, and/or a femtocell.In some implementations, base station 210 may send traffic to and/orreceive traffic from user device 205 via an air interface. In someimplementations, base station 210 may include a gNB associated with a 5Gnetwork that receives traffic from and/or sends traffic to SMSF 220 viaAMF 215.

AMF 215 includes one or more devices, such as one or more serverdevices, capable of managing authentication, activation, deactivation,and/or mobility functions associated with a user device 205 connected tothe 5G network. In some implementations, AMF 215 may perform operationsrelating to authentication of user device 205. AMF 215 may performoperations associated with handing off user device 205 from a first basestation 210 to a second base station 210 when user device 205 istransitioning from a first cell associated with the first base station210 to a second cell associated with the second base station 210.Additionally, or alternatively, AMF 215 may select another AMF (notpictured), to which user device 205 should be handed off (e.g., whenuser device 205 moves out of range of AMF 215). In some implementations,AMF 215 may communicate with a user device 205 (e.g., via base station210) to obtain information concerning a reachability of user device 205and may send the information to NEF 230. In some implementations, AMF215 may transfer traffic, such as audio, video, text, one or moremessages, and/or other traffic, to or from user device 205 (e.g., viabase station 210), SMSF 220, and/or NEF 230.

SMSF 220 includes one or more devices, such as one or more serverdevices, capable of facilitating transmission of messages, such as SMSmessages, to and from user device 205, AMF 215, UDM 225, NEF 230, and/orAF 255. In some implementations, SMSF 220 may be connected to NEF 230via a direct connection. In some implementations, SMSF 220 may receive amessage and convert the message to a different format and send themessage after converting the message. In some implementations, SMSF 220may send a paging request to user device 205 and/or receive a pagingresponse from user device 205.

UDM 225 includes one or more devices, such as one or more serverdevices, capable of registering and storing profile informationassociated with a user device 205 connected to the 5G network. In someimplementations, UDM 225 may store information concerning at least onecommunication capability of user device 205. In some implementations,UDM 225 may send the information concerning the at least onecommunication capability of user device 205 to NEF 230.

NEF 230 includes one or more devices, such as one or more serverdevices, capable of exposing capabilities, events, information, and/orthe like in the 5G network to help other devices in the 5G discovernetwork resources and/or utilize network resources efficiently. In someimplementations, NEF 230 may receive one or more messages from and/orsend one or more messages to a user device 205 via AMF 215 and basestation 210, and receive messages from and/or send messages to AF 255.In some implementations, NEF 230 may receive a message and convert themessage to a different format and send the message after converting themessage. In some implementations, NEF 230 may obtain a list of aplurality of user devices from AMF 215 and determine a reachability ofuser device 205 based on the list of the plurality of user devices. Insome implementations, NEF 230 may obtain information concerning at leastone communication capability of user device 205 from UDM 225.

SBI adaptor 235 includes one or more components of NEF 230. In someimplementations, SBI adaptor 235 includes one or more network devices,such as one or more server devices, capable of receiving, generating,storing, processing (e.g., converting), and/or providing messages, suchas messages described herein. In some implementations, SBI adaptor 235may facilitate converting a message of a first format (e.g., an SMSformat) to a second format (e.g., an SBI format).

SMS adaptor 240 includes one or more components of NEF 230. In someimplementations, SMS adaptor 240 includes one or more network devices,such as one or more server devices, capable of receiving, generating,storing, processing (e.g., converting), and/or providing messages, suchas messages described herein. For example, SMS adaptor 240 mayfacilitate transmitting a message received from an originating userdevice 205 to a destination user device 205 via AMF 215 and/or to AF255. In some implementations, the SMS adaptor 240 may facilitateconverting a message of a first format (e.g., an SBI format) to a secondformat (e.g., an SMS format).

AF message handler 245 includes one or more components of NEF 230. Insome implementations, AF message handler 245 includes one or morenetwork devices, such as one or more server devices, capable ofreceiving, generating, storing, processing (e.g., converting), and/orproviding messages, such as messages described herein. For example, theAF message handler 245 may facilitate transmitting a message to or fromAF 255.

Routing data structure 250 includes one or more components of NEF 230.In some implementations, routing data structure 250 includes one or moredevices capable of receiving, generating, storing, processing, and/orproviding information, such as information described herein. Forexample, routing data structure 250 may include a server device (e.g., ahost server, a web server, an application server, etc.), a data centerdevice, or a similar device. In some implementations, routing datastructure 250 may store the list of the plurality of user devices, oneor messages, and/or the like for retrieval by NEF 230.

AF 255 includes one or more devices capable of receiving, generating,storing, processing, and/or providing information, such as informationdescribed herein. For example, AF 255 may include a server device (e.g.,a host server, a web server, an application server, etc.), a data centerdevice, or a similar device. In some implementations, AF 255 may sendinformation, such as a message, to NEF 230 and receive information, suchas a message, a delivery message, and/or the like from NEF 230.

The number and arrangement of devices and networks shown in FIG. 2 areprovided as an example. In practice, there may be additional devicesand/or networks, fewer devices and/or networks, different devices and/ornetworks, or differently arranged devices and/or networks than thoseshown in FIG. 2. Furthermore, two or more devices shown in FIG. 2 may beimplemented within a single device, or a single device shown in FIG. 2may be implemented as multiple, distributed devices. Additionally, oralternatively, a set of devices (e.g., one or more devices) ofenvironment 200 may perform one or more functions described as beingperformed by another set of devices of environment 200.

FIG. 3 is a diagram of an example environment 300 illustrating at leastone benefit of some implementations described herein. As shown in FIG.3, an “indirect” message transmission path 302 (e.g., as currentlyimplemented by some telecommunication system providers) for a message(e.g., an SMS message) transmitting from an originating user device(e.g., shown as an “NSA-SA UE” or an “SA UE”) requires the message to berouted to an AMF and to an SMSF of a 5G telecommunications system (e.g.,shown as “5G SA Core”), to an SMSC of a 4G telecommunications system(e.g., shown as “4G EPC Core”), and to a NEF (e.g., shown as “SCEF/NEF”)of the 5G telecommunications system. In contrast, a “direct” messagetransmission path 304 (e.g., as provided by some implementationsdescribed herein) allows a message to be routed to an AMF, to an SMSF,and to a NEF of the 5G telecommunications system. In this way, themessage can be directly routed through the same 5G telecommunicationssystem without being routed to or from another telecommunicationssystem.

As indicated above, FIG. 3 is provided merely as an example. Otherexamples can differ from what was described with regard to FIG. 3.

FIG. 4 is a diagram of example components of a device 400. Device 400may correspond to user device 205, base station 210, AMF 215, SMSF 220,UDM 225, NEF 230, SBI adaptor 235, SMS adaptor 240, AF message handler245, routing data structure 250, and/or AF 255. In some implementations,user device 205, base station 210, AMF 215, SMSF 220, UDM 225, NEF 230,SBI adaptor 235, SMS adaptor 240, AF message handler 245, routing datastructure 250, and/or AF 255 may include one or more devices 400 and/orone or more components of device 400. As shown in FIG. 4, device 400 mayinclude a bus 410, a processor 420, a memory 430, a storage component440, an input component 450, an output component 460, and acommunication interface 470.

Bus 410 includes a component that permits communication among thecomponents of device 400. Processor 420 is implemented in hardware,firmware, or a combination of hardware and software. Processor 420 is acentral processing unit (CPU), a graphics processing unit (GPU), anaccelerated processing unit (APU), a microprocessor, a microcontroller,a digital signal processor (DSP), a field-programmable gate array(FPGA), an application-specific integrated circuit (ASIC), or anothertype of processing component. In some implementations, processor 420includes one or more processors capable of being programmed to perform afunction. Memory 430 includes a random access memory (RAM), a read onlymemory (ROM), and/or another type of dynamic or static storage device(e.g., a flash memory, a magnetic memory, and/or an optical memory) thatstores information and/or instructions for use by processor 420.

Storage component 440 stores information and/or software related to theoperation and use of device 400. For example, storage component 440 mayinclude a hard disk (e.g., a magnetic disk, an optical disk, amagneto-optic disk, and/or a solid state disk), a compact disc (CD), adigital versatile disc (DVD), a floppy disk, a cartridge, a magnetictape, and/or another type of non-transitory computer-readable medium,along with a corresponding drive.

Input component 450 includes a component that permits device 400 toreceive information, such as via user input (e.g., a touch screendisplay, a keyboard, a keypad, a mouse, a button, a switch, and/or amicrophone). Additionally, or alternatively, input component 450 mayinclude a sensor for sensing information (e.g., a global positioningsystem (GPS) component, an accelerometer, a gyroscope, and/or anactuator). Output component 460 includes a component that providesoutput information from device 400 (e.g., a display, a speaker, and/orone or more light-emitting diodes (LEDs)).

Communication interface 470 includes a transceiver-like component (e.g.,a transceiver and/or a separate receiver and transmitter) that enablesdevice 400 to communicate with other devices, such as via a wiredconnection, a wireless connection, or a combination of wired andwireless connections. Communication interface 470 may permit device 400to receive information from another device and/or provide information toanother device. For example, communication interface 470 may include anEthernet interface, an optical interface, a coaxial interface, aninfrared interface, a radio frequency (RF) interface, a universal serialbus (USB) interface, a wireless local area network interface, a cellularnetwork interface, or the like.

Device 400 may perform one or more processes described herein. Device400 may perform these processes based on processor 420 executingsoftware instructions stored by a non-transitory computer-readablemedium, such as memory 430 and/or storage component 440. Acomputer-readable medium is defined herein as a non-transitory memorydevice. A memory device includes memory space within a single physicalstorage device or memory space spread across multiple physical storagedevices.

Software instructions may be read into memory 430 and/or storagecomponent 440 from another computer-readable medium or from anotherdevice via communication interface 470. When executed, softwareinstructions stored in memory 430 and/or storage component 440 may causeprocessor 420 to perform one or more processes described herein.Additionally, or alternatively, hardwired circuitry may be used in placeof or in combination with software instructions to perform one or moreprocesses described herein. Thus, implementations described herein arenot limited to any specific combination of hardware circuitry andsoftware.

The number and arrangement of components shown in FIG. 4 are provided asan example. In practice, device 400 may include additional components,fewer components, different components, or differently arrangedcomponents than those shown in FIG. 4. Additionally, or alternatively, aset of components (e.g., one or more components) of device 400 mayperform one or more functions described as being performed by anotherset of components of device 400.

FIGS. 5A-5B are diagrams of example call flows of example operationscapable of being performed by one or more devices of FIG. 2 and/or oneor more components of one or more devices of FIG. 2. For example, FIG.5A is a diagram of an example call flow 500 for an application function(e.g., AF 255) to send a message to a destination user device (e.g.,user device 205-1). As another example, FIG. 5B is a diagram of anexample call flow 550 for an originating user device (e.g., user device205-1) to send a message to an application function (e.g., AF 255).

As shown in FIG. 5A and by reference number 502, user device 205-1 maysend a registration message to UDM 225 to provide information concerninguser device 205-1, such as at least one communication capability of userdevice 205-1. As shown by reference number 504, AF 255 may send amessage to NEF 230 in a similar manner as described herein in relationto FIG. 1B. As shown by reference number 506, NEF 230 may communicatewith UDM 225 to determine a communication capability of user device205-1 in a similar manner as described herein in relation to FIG. 1B. Asshown by reference number 508, NEF 230 may process the message anddetermine to send the message to user device 205-1 via SMSF 220 (e.g.,via a direct connection between NEF 230 and SMSF 220) in a similarmanner as described herein in relation to FIG. 1B. As shown by referencenumber 510, NEF 230 may send the message to SMSF 220 in a similar manneras described herein in relation to FIG. 1B.

As shown by reference number 512, SMSF 220 may send a paging request touser device 205-1 and receive a paging response from user device 205-1in a similar manner as described herein in relation to FIG. 1B. As shownby reference number 514, SMSF 220 may send the message to user device205-1 in a similar manner as described herein in relation to FIG. 1C. Asshown by reference number 516, NEF 230 may receive a response messagefrom user device 205-1 in a similar manner as described herein inrelation to FIG. 1C. As shown by reference number 518, NEF 230 may sendan acknowledgment to user device 205-1 in a similar manner as describedherein in relation to FIG. 1D. As shown by reference number 520, NEF 230may send, based on the response message, a delivery message to AF 255 ina similar manner as described herein in relation to FIG. 1C.

As shown in FIG. 5B and by reference number 552, a user device 205-1 maysend a registration message to UDM 225 to provide information concerninguser device 205-1 in a similar manner as described herein in relation toFIG. 5A. As shown by reference number 554, user device 205-1 may decideto send a message in a similar manner as described herein in relation toFIG. 1E. As shown by reference number 556, user device 205-1 may send amessage service request to NEF 230. NEF 230 may determine that NEF 230is capable of receiving and/or transmitting a message from user device205-1 and may grant the message service request.

As shown by reference number 558, user device 205-1 may send the messageto NEF 230 in a similar manner as described herein in relation to FIG.1E (e.g., via the direct connection between NEF 230 and SMSF 220). Asshown by reference number 560, NEF 230 may process the message anddetermine that the message is intended for AF 255 in a similar manner asdescribed herein in relation to FIG. 1E. As shown by reference number562, NEF 230 may send the message to AF 255 in a similar manner asdescribed herein in relation to FIG. 1F. As shown by reference number564, NEF 230 may send an acknowledgment to user device 205-1 in asimilar manner as described herein relation to FIG. 1F.

As indicated above, FIGS. 5A-5B are provided merely as examples. Otherexamples can differ from what was described with regard to FIGS. 5A-5B.

FIG. 6 is a flow chart of an example process 600 for communicatingmessages within a 5G network. In some implementations, one or moreprocess blocks of FIG. 6 may be performed by a device, such as a networkexposure function (e.g., NEF 230), and/or one or more components of thedevice, such as a service based interface (SBI) adaptor (e.g., SBIadaptor 235), a short message service (SMS) adaptor (e.g., SMS adaptor240), an application function message handler (e.g., AF message handler245), and/or a routing data structure (e.g., routing data structure250). In some implementations, one or more process blocks of FIG. 6 maybe performed by another device or a group of devices separate from orincluding the network exposure device, such as a user device (e.g., userdevice 205), a base station (e.g., base station 210), a network device,such as an access and mobility management function (e.g., AMF 215), anSMS function (e.g., SMSF 220), a unified data management (e.g., UDM225), and/or an application function (e.g., AF 255). A device mayperform one or more steps associated with a process block of FIG. 6using processor 420, memory 430, storage component 440, input component450, output component 460, communication interface 470, and/or the likeof the device.

As shown in FIG. 6, process 600 may include receiving, from anapplication function device (AF), a first message intended for a firstdestination user device (block 610). For example, the network exposuredevice may receive, from an AF, a first message intended for a firstdestination user device, as described above. The network exposure devicemay receive the first message from the AF via an SBI between the networkexposure device and the AF. In some implementations, the first messageconforms to a first format, such as a service based interface (SBI)format, a representational state transfer (REST) application programminginterface (API) format, and/or the like.

As further shown in FIG. 6, process 600 may include obtaining, from aunified data management device (UDM), information indicating acommunication capability of the first destination user device (block620). For example, the network exposure device may obtain, from a UDM,information indicating a communication capability of the firstdestination user device, as described above. The information indicatingthe communication capability may indicate that the first destinationuser device is capable of receiving messages that conform to a secondformat, such as a non-access stratum (NAS) format (e.g., a NAS SMSformat), an SMS format, and/or the like. In some implementations, thenetwork exposure device may send, to the UDM, information identifyingthe first destination user device and may receive, after sending theinformation identifying the first destination user device, theinformation indicating the communication capability of the firstdestination user device.

As further shown in FIG. 6, process 600 may include processing, based onthe information indicating the communication capability of the firstdestination user device, the first message (block 630). For example, thenetwork exposure device may process, based on the information indicatingthe communication capability of the first destination user device, thefirst message, as described above. In some implementations, the networkexposure device may process the first message to cause the first messageto conform to the second format (e.g., convert the first message fromthe first format to the second format).

As further shown in FIG. 6, process 600 may include sending, afterprocessing the first message, the first message to an SMS functiondevice (SMSF) via a direct connection with the SMSF to cause the SMSF tosend the first message to the first destination user device (block 640).For example, the network exposure device may send, after processing thefirst message, the first message to an SMS function device (SMSF) via adirect connection between the network exposure device and the SMSF tocause the SMSF to send the first message to the first destination userdevice, as described above. The SMSF may send the first message to thefirst destination user device after the SMSF communicates with the firstdestination user device in accordance with a paging procedure. Thedirect connection may be a NAS interface, a REST API, and/or the like.In some implementations, the network exposure device may add the firstmessage to a payload of a REST API message and send the REST API messageto the SMSF via the direct connection.

In some implementations, the network exposure device may determine,before sending the first message to the SMSF via the direct connection,a location associated with the destination user device and may select,based on the location associated with the destination user device, theSMSF, from a plurality of SMFS, to receive the first message from thenetwork exposure device.

As further shown in FIG. 6, process 600 may include receiving, from theSMSF and via the direct connection, a response message indicating thatthe first destination user device received the first message (block650). For example, the network exposure device may receive, from theSMSF and via the direct connection, a response message indicating thatthe first destination user device received the first message, asdescribed above. The response message may concern receipt of the messageby the destination user device. In some implementations, the networkexposure device may send, based on the response message, anacknowledgment to the SMSF via the direct connection to cause the SMSFto send the acknowledgment to the first destination user device.

As further shown in FIG. 6, process 600 may include sending, to the AF,a delivery message indicating that the first destination user devicereceived the first message (block 660). For example, the networkexposure device may send, to the AF, a delivery message indicating thatthe first destination user device received the first message, asdescribed above. In some implementations, the delivery message indicatesthat the first message was successfully delivered to the destinationuser device.

As further shown in FIG. 6, process 600 may include receiving, from theSMSF, a second message intended for a second destination user device(block 670). For example, the network exposure device may receive, fromthe SMSF, a second message intended for a second destination userdevice, as described above. In some implementations, the second messageconforms to the second format. In some implementations, the networkexposure device may send, based on receiving the second message, anacknowledgment to the SMSF via the direct connection.

As further shown in FIG. 6, process 600 may include determining areachability of the second destination user device (block 680). Forexample, the network exposure device may determine a reachability of thesecond destination user device, as described above. The network exposuredevice may determine a reachability status of the additional destinationuser device; determine a time when the additional destination userdevice is reachable; determine a duration of time the additionaldestination user device is reachable; determine a schedule of when theadditional destination user device is reachable; determine areachability start time of the additional destination user device; ordetermine a reachability end time of the additional destination userdevice.

In some implementations, the network exposure device may obtain, from anaccess and mobility management function device (AMF), a list of aplurality of user devices that indicates a respective reachability of atleast one user device of the plurality of user devices and maydetermine, based on the list of the plurality of user devices, thereachability of the second destination user device.

As further shown in FIG. 6, process 600 may include sending the secondmessage to the SMSF via the direct connection to cause the SMSF to sendthe second message to the second destination user device (block 690).For example, the network exposure device may send the second message tothe SMSF via the direct connection between the network exposure deviceand the SMSF to cause the SMSF to send the second message to the seconddestination user device, as described above. The network exposure devicemay send the second message to the SMSF based on the reachability of thesecond destination user device. In some implementations, when the secondmessage is an SMS transfer protocol data unit (TPDU) message, thenetwork exposure device may convert the second message into a REST APImessage and send, after converting the second message into the REST APImessage, the second message to the SMSF via the direct connection tocause the SMSF to send the second message to the second destination userdevice.

Additionally, or alternatively, in some implementations, the secondmessage is intended for the AF and the network exposure device may sendsecond message to the AF. The network exposure device may convert thesecond message (e.g., from the second format to the first format, suchfrom an NAS format to an SBI format) before sending the second messageto the AF to allow the second message to be transmitted to and/orreceived by the AF.

Process 600 may include additional implementations, such as any singleimplementation or any combination of implementations described inconnection with one or more other processes described elsewhere herein.

Although FIG. 6 shows example blocks of process 600, in someimplementations, process 600 may include additional blocks, fewerblocks, different blocks, or differently arranged blocks than thosedepicted in FIG. 6. Additionally, or alternatively, two or more of theblocks of process 600 may be performed in parallel

The foregoing disclosure provides illustration and description, but isnot intended to be exhaustive or to limit the implementations to theprecise form disclosed. Modifications and variations may be made inlight of the above disclosure or may be acquired from practice of theimplementations.

As used herein, the term “component” is intended to be broadly construedas hardware, firmware, or a combination of hardware and software.

To the extent the aforementioned implementations collect, store, oremploy personal information of individuals, it should be understood thatsuch information shall be used in accordance with all applicable lawsconcerning protection of personal information. Additionally, thecollection, storage, and use of such information can be subject toconsent of the individual to such activity, for example, through wellknown “opt-in” or “opt-out” processes as can be appropriate for thesituation and type of information. Storage and use of personalinformation can be in an appropriately secure manner reflective of thetype of information, for example, through various encryption andanonymization techniques for particularly sensitive information.

It will be apparent that systems and/or methods, described herein, maybe implemented in different forms of hardware, firmware, and/or acombination of hardware and software. The actual specialized controlhardware or software code used to implement these systems and/or methodsis not limiting of the implementations. Thus, the operation and behaviorof the systems and/or methods were described herein without reference tospecific software code —it being understood that software and hardwarecan be used to implement the systems and/or methods based on thedescription herein.

Even though particular combinations of features are recited in theclaims and/or disclosed in the specification, these combinations are notintended to limit the disclosure of various implementations. In fact,many of these features may be combined in ways not specifically recitedin the claims and/or disclosed in the specification. Although eachdependent claim listed below may directly depend on only one claim, thedisclosure of various implementations includes each dependent claim incombination with every other claim in the claim set.

No element, act, or instruction used herein should be construed ascritical or essential unless explicitly described as such. Also, as usedherein, the articles “a” and “an” are intended to include one or moreitems, and may be used interchangeably with “one or more.” Furthermore,as used herein, the term “set” is intended to include one or more items(e.g., related items, unrelated items, a combination of related andunrelated items, etc.), and may be used interchangeably with “one ormore.” Where only one item is intended, the phrase “only one” or similarlanguage is used. Also, as used herein, the terms “has,” “have,”“having,” or the like are intended to be open-ended terms. Further, thephrase “based on” is intended to mean “based, at least in part, on”unless explicitly stated otherwise.

What is claimed is:
 1. A device, comprising: one or more processors,configured to: receive, from an application function (AF), a messageintended for a destination user device, wherein the message conforms toa service based interface (SBI) format; send, to a unified datamanagement device (UDM), a query concerning a messaging capability ofthe destination user device; receive, from the UDM and based on sendingthe query, a response that indicates that the destination user device iscapable of receiving messages that conform to a non-access stratum (NAS)format; convert, based on the response that indicates that thedestination user device is capable of receiving messages that conform tothe NAS format, the message from the SBI format to the NAS format; andsend, after converting the message from the SBI format to the NASformat, the message to a short message service function device (SMSF)via a direct connection between the device and the SMSF, wherein theSMSF sends the message to the destination user device.
 2. The device ofclaim 1, wherein the one or more processors are further configured to:receive, from the SMSF, after sending the message to the SMSF via thedirect connection between the device and the SMSF, and via the directconnection between the device and the SMSF, a response messageconcerning receipt of the message by the destination user device; andsend, to the AF and based on the response message, a delivery messageconcerning delivery of the message to the destination user device. 3.The device of claim 2, wherein the response message indicates that thedestination user device received the message, and wherein the deliverymessage indicates that the message was successfully delivered to thedestination user device.
 4. The device of claim 1, wherein the one ormore processors are further configured to: receive, from the SMSF, anadditional message intended for the AF, wherein the additional messageconforms to the NAS format; convert the additional message from the NASformat to the SBI format; and send the additional message to the AF. 5.The device of claim 1, wherein the SBI format is a representationalstate transfer (REST) application programming interface (API) format andthe NAS format is a NAS short message service (SMS) format.
 6. Thedevice of claim 1, wherein the one or more processors, when receivingthe message intended for the destination user device, are configured to:receive the message from the AF via an SBI between the device and theAF, wherein the one or more processors, when sending the message to theSMSF via the direct connection between the device and the SMSF, are to:send the message to the SMSF via a direct NAS interface between thedevice and the SMSF.